Update deploy workflow to explicitly use SSH key for gh-pages deployment

Author: vaqm2

.github/workflows/deploy.yml

@@ -23,7 +23,15 @@ jobs:
           npm run build
 
       - name: Deploy 🚀
+        env:
+          # Set GIT_SSH_COMMAND to use the SSH key from secrets
+          GIT_SSH_COMMAND: "ssh -i ~/.ssh/id_rsa -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no"
         run: |
+          # Create the .ssh directory and add the private key
+          mkdir -p ~/.ssh
+          echo "${{ secrets.GH_PAGES_DEPLOY_KEY }}" > ~/.ssh/id_rsa
+          chmod 600 ~/.ssh/id_rsa
+
           git config --global user.name 'github-actions-bot'
           git config --global user.email 'support+actions@github.com'
-          npx gh-pages -d build -r git@github.com:${{ github.repository }}.git
+          npx gh-pages -d build -r git@github.com:${{ github.repository }}.git